This invention is for securing a beam trolley on an I-beam or H-beam. More particularly, this invention is to a adjustable width beam hoist trolley having a manually activated friction brake to selectively and safely secure a loaded or unloaded beam trolley at a selected position along the length of the beam.
Adjustable beam trolleys are industry standard devices for permanent or temporary mounting of a hoist on a standard I-beam or H-beam. The beam trolleys provide vertical support and permit linear motion of the supported load as the trolley rolls along the length of the beam. Many adjustable beam trolleys are commercially available from a number of manufacturers and are called adjustable because they can be adjusted to accommodate differently sized I and H beams. FIGS. 1 and 2 show a typical commercially available adjustable beam trolley 10 having a pair of steel side plates 11 shaped with end-bumpers 12, and each side plate 11 mounts a pair of load bearing trolley wheels 13 on steel axles 14. A heavy-duty threaded steel bolt 15, having secured end-nuts 16 abutting the outsides of side plates 11, laterally extends through round openings (not shown) provided in both of side plates 11 and aligned bores (not shown) in inward extensions 17 of side plates 11. A steel load bearing hoist mount 18 is mounted midway on threaded bolt 15 where it extends between inward extensions 17 to receive and support a manual or automatic chain hoist connected to a load (not shown).
FIG. 2 shows in greater detail that an appropriate number of spacer washers 19 optionally can be provided on threaded bolt 15 on opposite sides of hoist mount 18. Spacer washers 19 assure the right separation of side plates 11 and trolley wheels 13 to properly fit beam trolley 10 on beam 20. This proper fit on beam 20 places the outer circumferential surfaces 21 of trolley wheels 13 on upper web surfaces 22 of beam 20 so that wheels 13 engage and longitudinally ride along beam 20 and transfer the load's weight to beam 20 via beam trolley 10. End nuts 16 are securely tightened on threaded bolt 16 to secure these components together when they have been properly fitted.
The contemporary beam trolleys such as those described above do not have a suitable operator-controlled means for fixedly securing them to the load bearing beams. This can create unsafe lifting of loads by the trolley and hazardous stowage of an unused, unsecured trolley under unstable ambient conditions, such as on those encountered on a ship underway at sea.
Thus, in accordance with this inventive concept, a need has been recognized in the state of the art for an operator actuated means to secure a beam trolley to a load bearing beam to prevent unwanted travel of the trolley along the beam.